SPA — Triticum aestivum

Summary

TRAESCS1D02G332200 (symbol SPA, also known as RISBZ1) on bread wheat chromosome 1D encodes a bZIP domain-containing protein with DNA-binding transcription factor activity and protein dimerization activity, localised to the nucleus. The gene is associated with the regulation of starch biosynthetic processes and nitrogen storage, as well as responses to cold temperature and abiotic stimuli. It has been linked to a wide range of agronomically important traits, including spike density, grain iron and zinc content, grain weight per spike, amylose content, test weight, grain texture and color, flag leaf senescence, plant vigor, stand establishment, drought sensitivity, harvest index, and grain yield per plant. The gene also shows connections to grain protein concentration and seed weight. Studies of related genes in other species, such as CPRF2 and BZIP15, further support the family's role in transcriptional regulation.